Presented here are many ways the experimenter may assemble electronic circuits.
Some are inexpensive and easy to make from readily available materials. Others
are more expensive, not very reliable or perhaps even obsolete. All of these
techniques are showcased here because it is useful to be aware of all the possibilities
and options. When in a pinch or a hurry, you can resort to the technique that
best suits the situation.

Point-to-point wiring

Components are wired directly and suspended in air or mounted on an insulating
material such acrylic, Plexiglas or Lucite. Components may also be soldered
to metal terminals or posts mounted on teflon standoffs. This technique is used
when dealing with very high voltages in excess of 1KV or higher or when you
want the lowest possible leakage currents.

Applications

Advantages

Disadvantages

High voltage, power components, ultra low leakage currents

Simple, no special hardware required

Bulky, not suitable for complex circuits

Terminal Posts

Metal posts are commercially available which can be mounted in many types of
insulating materials. Component leads and wires are wrapped around the posts
and then soldered to create a sturdy joint.

Applications

Advantages

Disadvantages

High voltage, power components, ultra low leakage currents

Simple, no special hardware required

Bulky, not suitable for complex circuits

Tag/Lug/Terminal Strip

When assembling bulky components such as large power resistors, rectifiers,
capacitors, transformers (you guessed it - as in building a power supply) it
may be easier to just bolt or screw terminal tags or lugs on to the chassis,
whether metal or wood.

Applications

Advantages

Disadvantages

Power supplies

Simple, low cost construction

Bulky, not suitable for small components

Breadboard and screws

This is perhaps the origin of the first "breadboard". It is the simplest,
cheapest, easy to make and modify, durable, robust and perfect for school projects
and classroom demonstrations. Now, don't go and use mom's breadboard if you
want to eat dinner tonight but get yourself a scrap piece of softwood like white
pine, about 1cm or 1/2" thick and any suitable size. Of course, if you
choose to use plywood instead, this is called SOP technology, or Silicon-On-Plywood
: )

Sand the edges to remove any splinters. Find some #6 x 1/2" pan head metal
screws and you're all set to go. You can mount the screws any place you like
or you can pre-drill the board with 3/32" holes on a 1" grid pattern.
Flat washers on every screw will help to secure your wires.

Applications

Advantages

Disadvantages

Prototype, school projects, classroom demonstrations

Simple, no special hardware required

Bulky, not suitable for complex circuits

Battery Terminals

You can be creative by reusing old battery thumb caps. These are perfect for
creating classroom demonstrations.

Applications

Advantages

Disadvantages

Prototype, school projects, classroom demonstrations

Simple, low cost, readily available material

Bulky, not suitable for complex circuits

DEC Jumper Cables

Here is a great way to get young folks involved in building electronic circuits.
I happen to have a large collection of DEC (Digital Equipment Corporation) jumper
cables with mini-banana plugs on the ends from olden days of using DEC Flip-Chips®.
I have put these to good use by creating various modules with lights, switches,
meters, motors, battery holders and even those annoying greeting card noise
makers. The nice thing about these plugs is that they are stackable, allowing
you to plug one on top of another. Sockets are made by winding brass wire around
a suitably sized nail.

Applications

Advantages

Disadvantages

Prototype, school projects, classroom demonstrations

Simple, versatile, easy to rewire

Bulky, not suitable for complex circuits

Spring Clips

You may still be able to find a supply of these spring clips which plug into
perforated hardboard, Masonite or pegboard. The springs serve the same purpose
as terminal posts except you do not solder the joints, allowing for easy modification.
Component leads and wires are held in place by the metal springs.

Applications

Advantages

Disadvantages

Prototype, school projects, classroom demonstrations

Simple, versatile, easy to reconfigure

Bulky, not suitable for integrated circuits

Perf Board

Perforated phenolic or fibreglas boards can be used for point-to-point wiring
of leaded components. It is a good idea to use sockets for ICs to allow for
easy replacement of ICs. Wire wrap sockets will give you a longer pin to work
with.

Applications

Advantages

Disadvantages

General purpose discrete components and thru-hole ICs

Simple, no special hardware required

Time consuming

Foam Board

Here is a clever, creative and attractive way to construct hobby projects.
Standard foam board 5mm thick consists of foam sandwiched between two layers
of cardboard. Punch holes for leaded components and wire wrap sockets. Wire
the same way as for perf board construction.

Applications

Advantages

Disadvantages

General purpose discrete components and wire wrap sockets

Simple, low cost, attractive

Wire Wrap

With the advent of digital integrated circuits in DIP packages, there was the
need to assemble fairly complex designs with lots of connections. Wire wrap
techniques came to the rescue and entire mini-computers (e.g. DEC PDP-8, PDP-9,
PDP-15) were assembled using wire wrap. This and Scotchflex were the quickest
way of getting your prototype up and running. This technique is not particulary
useful for analog circuitry since component carriers have to be used for mounting
discrete components.

Applications

Advantages

Disadvantages

General purpose, digital circuits

Fast to assemble and easy to modify

Wire wrap sockets are expensive. Not good for discrete components.

Scotchflex®

The Scotchflex® breadboard system made by 3M is a great time-saving
method for prototyping large microprocessor systems that contain a large number
of peripheral components and memory chips. This system allows you to bus address,
data and control lines from chip to chip with a single wire without having to
strip, wrap or solder the wire. At the time of appearance on the market place,
this was a great idea which worked well for circuits using DIP components. Microcontrollers
today are fully integrated with an assortment of memory and peripherals and
hence have made this breadboarding system redundant.

As with wire-wrap sockets, you have to use component carriers to mount discrete
components.

Applications

Advantages

Disadvantages

Computer memory and bus systems

Fast prototyping of DIP components

Expensive, obsolete

Component Carriers

Component carriers are DIP (dual-inline package) plugs on to which you can
solder leaded components such as resistors, capacitors, diodes and transistors.
These can then be plugged into standard DIP sockets. These are handy, not only
for prototyping, but also if you want to be able to reconfigure your circuit
easily, for example, change the gain or roll-off frequency of an active filter.

Applications

Advantages

Disadvantages

Mounting leaded components into DIP sockets

Easy way to reconfigure a circuit

Polyurethane Enamel Coated Wire

Another method of speeding up the wiring of bussed systems is to use polyurethane
enamel coated copper wire or UEW. The wire can be dispensed from a simple hand
tool which can be homemade as demonstrated by other creative electronics enthusiasts.
The heat from the soldering iron melts the polyurethane plastic insulation on
the wire and bonds the wire to the solder joint. You keep soldering from point
to point and then cut off the wire at the end of the run.

Applications

Advantages

Disadvantages

All applications

Fast wiring of digital buses

Solderless "Superboard", "Superstrip", "Wishboard"

The solderless breadboard system is by far the most versatile system available
for prototyping both leaded and DIP components. Surface mount devices (SMD)
can also be included if you use SMD to DIP adapters or carriers. Prototyping
is fast, reliable and easy to modify. Every experimenter should have at least
one of these breadboards. For simple portable prototypes you can use a single
board and a 9V battery, 3V coin battery or AA or AAA battery packs. For the
serious experimenter, build yourself a larger board with three or four boards
on top and include a built-in power supply that provides 5V, +12V and -12V,
(or +15V and -15V). This will allow you to prototype both analog and digital
systems.

Applications

Advantages

Disadvantages

Experimenting, analog and digital circuits

Most versatile, easy to modify, leaded and DIP components

for prototyping only

ISA Prototyping Board

Well, here is an imaginative solution - a superboard stuck onto an ISA prototyping
card. This gives you all the versatility of the superboard while plugged permanently
into an PC. Unfortunately, this is now obsolete since they don't make PCs with
ISA slots anymore.

Applications

Advantages

Disadvantages

PC mounted prototyping

Versatile, enclosed in PC

Obsolete

Stripboard, Veroboard, Vectorboard

After prototyping on a superstrip, you can make your circuit reliable and permanent
using copper clad prototyping stripboards made by Vero and Vector. These boards
are available in different sizes and connection patterns. For versatility, you
can't beat the parallel copper tracks of stripboard. You cut away the copper
strips by hand as desired using either a sharp X-acto knife, drill bit, or special
hand tool. Interconnections are made using the copper strips by carefully choosing
the placement and layout of your components. Additional jumper wires are best
installed on the component side, unlike perf board construction. SMT resistors
and capacitors can be soldered on the copper side. Stripboard is the simplest
solution for both digital ICs and analog discrete components.

Applications

Advantages

Disadvantages

All applications, analog and digital

Good for leaded and DIP components

Can't think of any

Double sided copper laminate

For the ultimate in modern design, compactness, low noise and when you must
use surface mount technology (SMT), it is in fact quite easy to prototype using
SMT components. The end result is a circuit that has all of the advantages of
SMT and is clean of noise.

First, we take a suitably sized piece of double sided copper laminate. Since
we are talking about SMT, think small. You can put a lot of stuff on
a board 2" x 2" or even 1 square inch! The goal is to reserve the
bottom side of the board for a ground plane. All components are placed on the
top side. The copper circuit is created, not by cutting copper traces, but by
cutting away copper strips to create spaces about 0.020" to 0.050"
wide or what I call "anti-traces". This is quite easy to do using
a sharp X-acto knife. You score on the outline of the anti-trace you want
to strip off, usually a long rectangular channel, lift up the edge of one end
and peel away the copper strip. It peels off quite easily, easier than rolling
away a strip of sod off your lawn.

If your design does not require low signal noise and you want to make the board
even more compact you may choose to place components on both sides of the board.
Since cutting the copper layers by hand is time consuming, this is not recommended
for complex digital circuitry. It is possible to remove the copper using a fine
rotary tool. In fact, numerical control (NC) machines are available which will
mill out the anti-traces using information from a regular PCB layout program.

For resistors and capacitors, I like to stay with 0805-sized components since
they are easier to handle and I have a better chance of finding them when you
drop one on the floor. For integrated circuits, it is easier to work with components
in SOIC (Small Outline Integrated Circuit) packages, with 0.050" pitch.
Stay away from anything with MLP (Metric Lead-frame Package) since there are
no leads on these.

Cutting the anti-traces, laying out a neat design and soldering the components
to create your masterpiece can be a very satisfying experience.

Applications

Advantages

Disadvantages

Low noise SMT analog circuits

Compact, low noise SMT design

Not suitable for complex digital circuits

Printed Circuit Board

When you know that your prototype works and the design is frozen, nothing beats
the satisfaction of seeing your creation in a professionally made printed circuit
board (PCB). You can start out by making the boards yourself or you can take
advantage of the internet and have a commercial shop make it for you. With the
advent of the internet and higher demand these are actually not expensive to
have made, even for a single board.

Making a PCB yourself, while educational, is also time-consuming and messy.
Since it is reasonable to have it made commercially, let us examine that route.
Since it is easy to make mistakes in your electronic design and board layout,
it is not a bad idea to make a prototype first. Many PCB shops offer a special
prototyping service at lower costs. These boards are generally double sided
with plated holes but without silk screen overlay (component placement and part
identifiers) and solder masks (the green protective layer) in order to keep
costs low. Mainly because of the setup charge incurred you can expect to pay
around CAD$50 to CAD$75 to get a couple of boards made. Turn-around time is
usually short, one to three days at the most. After you have tested the prototype
and have corrected all your mistakes you can go ahead and make your first batch
of 100 production boards! Suffice to say that the experimenter rarely goes into
production and is happy to use the prototype service even for a dozen or more
boards.